New Yorkers are in for a treat today, as the annual Parade of Ships kicks off this year’s Fleet Week celebrations.

Three Navy ships and two Coast Guard cutters take center stage in New York Harbor this morning. A week of events follows, as 1,500 sailors, Marines and Coast Guardsmen invade our city’s streets.

It’s a chance for New Yorkers to enjoy the sights and welcome these men and women in uniform. It’s also a chance to remember the key role our “sea services” play in ensuring our freedom. Not to mention the great risk and sacrifice this requires.

Even before 9/11, one of the ships here this week — USS Cole — was struck and almost sunk by terrorists. Seventeen sailors were killed. Today their successors continue to stand between us and danger.

Americans will always be grateful to the brave Navy SEALs who nabbed Osama bin Laden in 2011, but their work continues too: Just last March, SEALs took back an oil tanker commandeered by Libyan militants.

And, of course, there are the two ex-SEALs who gave their lives in Benghazi.

Even in peacetime, our fleet patrols the world’s waters, helping project power and reminding enemies of our military prowess.

The risk to life aside, this means considerable personal sacrifice by sailors and Marines who increasingly are subject to more frequent and longer deployments that keep them apart from their families.

Our dependence on their service won’t soon wane. Threats and challenges continue to emerge — in the Pacific, the Mediterranean, the Persian Gulf and elsewhere. The least our city can do in appreciation is to show these men and women a good time.

New Yorkers can enjoy this week with them through military-band concerts, search-and-rescue demonstrations, aerial displays and more. The Intrepid Museum, housed in the retired carrier USS Intrepid, will have its own special events.

But it’s the sailors, Marines and Coast Guardsmen who come first this week. So if you see one, tip your hat — and extend them the hearty welcome they have earned.